Mino was downloaded millions of times, and Tetris Holding filed a DMCA notice and eventually a lawsuit against Xio for copyright infringement.

The district court ruled for Tetris Holding, with Judge Wolfson applying the Abstraction-Filtration-Comparison test to determine if any infringement occurred.

At that point Xio researched intellectual property law to see how to design a game similar to Tetris that would not include any legally-protected elements.

[5] The game Mino featured the same approach of using falling tetromino blocks to form complete lines on a playfield and score points.

[11] With the costs of filing a lawsuit being very high compared to the expected outcome, many video game copyright holders became hesitant to sue alleged clones.

In defending the copyright claim, Xio founder Desiree Golden admitted to having copied Mino directly from the official Tetris app that was developed under license by Electronic Arts.

The New Jersey district court was within the Third Circuit, which had prior case law from Whelan v. Jaslow (797 F.2d 1222 (1987)) that used a purpose-based test to abstract software to determine if copyright was infringed.

Wolfson further dismissed Golden's scènes à faire arguments, ruling that Tetris was a unique game and thus had no established stock or common imagery that would be ineligible for protection.

Where Mino's marketing used the same color and style of the pieces from Tetris, these details were distinct expression and not merely functional ideas in the public domain.

[9] Wolfson subsequently granted summary judgment in Tetris Holding's favor,[15] and entered an injunction that permanently prohibited Xio from distributing or marketing their game.

[6][11] Legal scholars have included this decision in a wave of cases that have pushed the boundaries of video game copyright protection, along with Electronic Arts Inc. v. Zynga Inc. from 2012.

[14] Nicholas Lampros also noted that the facts of this case were highly specific, leading to "a narrow, fact-heavy legal standard, the outcome of which is difficult to predict outside of court".

[6] Tom Phillips has noted that the high cost and uncertainty of fact-specific litigation has led developers to hold each other accountable in the media, as an alternative to legal action.

[19] By contrasting this case with early video game rulings such as Atari v. Amusement World, it is possible to see the difference between a free idea versus copyrightable expression.

[20] Scholars have argued that this case represents the game medium coming of age, evolving from rudimentary gameplay into sufficiently expressive systems that are worthy of copyright protection.

[14] Susan Corbett argues that "the Tetris decision supports the view that United States courts are becoming more accepting of the possibility of offering broader copyright protection for videogames".

[21] Tomasz Grzegorczyk notes that this case shows courts are willing to recognize that the "graphic user interface of the game is subject to protection under copyright in the same manner as audiovisual works".